Hinges are made from two metal plates that are attached together with a removable pin. The metal plates are attached to the door and door frame with screws. Hinges hold the door securely to the door frame and allow it to swing open and closed. There are numerous types and sizes of hinges for different applications. The base material is also different for different applications. Atlantic Elite offers 3? Steel Ball Bearing Hinges, 3? Stainless Steel Ball Bearing Hinges, 4? Grade 13 Fire Rated FD30/60 Fire Door Hinges, 3? Solid Brass Washered Hinges, 4? Solid Brass Parliament Hinges and 4? Mild Steel Grade 11 Fire Rated FD30/60 Fire Door Hinges in up to 15 finishes.